Method of making honeycomb structure with joined single pleat material

ABSTRACT

A honeycomb structure formed of two continuous lengths of pleated materials secured together intermediate the pleats. Each length of pleated material defines one side of the honeycomb structure. The two continuous lengths are secured together by feeding them longitudinally of their length and toward each other. At the location where the two lengths meet, they are joined together intermediate their pleats.

This is a division of application Ser. No. 796,035, filed Nov. 7, 1985.

BACKGROUND OF THE INVENTION

The present invention relates to an expandable honeycomb structure suchas used for window coverings. The structure is made of two separatepleated materials which are secured together so that when expanded, theydefine a plurality of longitudinally extending cells, one on top of theother. In the retracted state of the honeycomb structure, the adjacentcells are collapsed on each other.

The prior art discloses various honeycomb structures made generally froma single piece of foldable material. Representative of such prior artare Rasmussen U.S. Pat. Nos. Re. 30,254 and Re. 31,129, the patent toMasuda, U.S. Pat. No. 3,164,507, and the patent to Colson, U.S. Pat. No.4,450,027. The prior art also includes honeycomb structures fabricatedfrom separate sheets of material which are secured together to formindividual cells. Representative of this prior art are the patents toWhitney, U.S. Pat. No. 1,827,718, Hartsell et al, U.S. Pat. No.3,077,223, and the patents to Suominen, U.S. Pat. Nos. 4,288,485 and4,388,354.

A difficulty with all of the prior art constructions is the ability tomanufacture the honeycomb cells with opposite faces of differentphysical characteristics. This is sometimes desirable either foraesthetic of mechanical reasons. For example, thermal insulation againstheat or cold, besides that given by the cell structure, can be providedby appropriate surfacing of the material of the structure which facesthe elements. With the prior art constructions, as for example disclosedin the '027 patent, where a single piece of material is used to form thecells, different portions of the material which will ultimately definethe opposite sides of the structure have to be separately processedprior to the formation of the honeycomb configuration. Problems ofalignment of the differently treated surfaces can result in an inferioror unacceptable product. More particularly, the material must be fedaccurately and folded accurately along its length. Also, it must besecured to the adjacent cell in such a way as to cover the line ofdemarcation separating the two differently treated surfaces. Otherwise,the different surfaces will show through from one side of the structureto the other.

With the honeycomb structures such as disclosed in the Suominen patents,different sheets of material are used to form the structure. Thesematerials can obviously be made with different physical characteristics.However, this will not result in the opposite faces of the resultinghoneycomb structure having different physical characteristics. This isso because of the method of manufacture. In Suominen, the materials arefed longitudinally and secured together longitudinally at spacedlocations across the material. Therefore, in the expanded honeycombstructure, the opposite faces will be formed partially by one materialand partially by the other material. Again, in order to have one entireside of the honeycomb structure provided with physical characteristicsdifferent from the other side, each material must be processeddifferently across its width in the same way as required with the singlepiece of material which is folded to form the cells of the honeycombstructure.

Another aspect of the honeycomb structures of the prior art relates tothe creasing or pleating of the material forming each cell. One reasonpleating is provided is to assist in the orderly collapsing of theindividual cells as the structure is moved between an expanded andretracted position. Without pleats, the collapsing of the cells wouldtend to be haphazard and not give a neat appearance to the structure. Inthe cell construction disclosed in the '027 patent, the pleats areformed to be permanent so that the faces of the honeycomb structureextend in angular configuration in the expanded condition of thestructure. If the pleats are not carefully and properly formed, theywill tend to hang out. This is especially so after long, continued useof the structure, with the expanded condition being one where the cellslie one below the other. In such an orientation, the weight of thestructure itself pulls on the material of the overlying cells with thegreatest forces being exerted at the top of the structure by the entireweight of the underlying cells Any falling out of the pleats tends toincrease the overall height of the structure over the height asinitially manufactured. The effect of this can be unpleasing andunsatisfactory, both aesthetically and physically.

The honeycomb structures disclosed in the prior art cited above may bemade of very thin material where, for example, a translucent effect isdesired. With very thin material care must be taken in the choice ofadhesive that is used and the manner in which it is applied. This isimportant, not only from the manufacturing aspects but also from thestandpoint of durability of the resulting structure. With regard tomanufacturing, too much adhesive or the wrong kind of adhesive andsomewhat porous cell material can cause bleeding of the adhesive throughthe material. With the prior art structures where the secured materialsare wound in layers upon each other, bleeding of adhesive through thematerial can cause successive layers to become adhered to each other soas to produce cells which are glued closed and will not normally open.This can either destroy the product or require extra procedures toseparate the layers and open the cells. As far as durability isconcerned, the adhesives chosen must, in many instances, be capable ofwithstanding the severe heat and sunlight when used in windows. Thecompatability of such adhesives which give proper durablity is notalways the best as far as avoiding manufacturing bleedthrough problems.

SUMMARY OF THE PRESENT INVENTION

According to the teachings of the present invention, anexpandable-collapsible honeycomb structure is provided from two pleatedlengths of material, one of these materials will form one side of thehoneycomb structure, while the other will form the other side. Thus,they can be made of the same or different material. Also, the pleats inthe material can be formed as part of the honeycomb forming process orcan be preformed. In any event, the pleated materials are securedtogether along the pleats. This connection can be effected while thepleated materials are in partially expanded condition, whereby anybleedthrough of adhesive will not contact adjacent sections of thematerials and improperly cause these sections to become attached to eachother. The materials used can be any foldable material such as disclosedin U.S. Pat. No. 4,450,027, those made of non-woven fibers of polyesteror woven materials from plastic or textile fibers plus plastic. Also,laminates can be used. With these materials it will be the absorbtion inand through a somewhat porous layer that creates the bleeding throughproblem of the prior art.

In addition, with applicant's invention, the two pieces of materialforming the opposite faces of the cells can be secured together byseparate strip materials extending longitudinally between the cells. Theadvantage of this is that the strip materials can be chosen so as topermit a wider choice of adhesives. For example, the strip materials canbe more impermeable or thicker than the materials from which the rest ofthe honeycomb structure is fabricated. Also, the use of strip materialsto connect the opposite faces of the cells of the honeycomb structurefacilitates spacing of the opposite faces from each other. This in turn,gives the resulting cell structures better insulating qualities and alsoprovides internal area for concealment of the associated cords andoperating mechanism to be used with the honeycomb structure.

The pleats in the two pieces of material from which the honeycombstructure is made can also be formed intermediate the points ofattachment of the two pieces of material. These pleats are formed alongfold lines extending longitudinally of the cells and these fold linescan be creased to produce permanent pleats which will retain their shapein the expanded condition of the cells. Alternatively, the pleats can beformed to be sufficient merely to guide the folding and unfolding of thematerial along the creases in an orderly manner as the honeycombstructure is collapsed and expanded.

Where it is desired to assure the maintenance of the pleated conditionin the honeycomb structure, the present invetion is of great advantage.By having the opposite sides of the structure formed from separateindependent materials, stresses at the points of attachment of theadjacent cells are kept to a minimum. These stresses are particularlytroublesome where adhesive is used to effect this attachment and thehoneycomb structure is suspended with the cells one below the otherpulling on the cells above. With the construction of the presentinvention, the stresses placed on the cell joints are mainly thoserequired to keep the two pieces of material attached horizontally at thejoint locations. The vertical pulling forces resulting from hanging thehoneycomb structure tend to pass from cell to cell by simply pulling onthe two pieces of material separately of each other. Also, one side ofthe structure can be formed with permanent creases, while the otherformed with light creases which will hang out in the expanded conditionof the honeycomb structure. This other side will also be formed with anamount of material which is less than that on the pleated side, so thatin the fully expanded condition of the structure, the faces of the cellson the lightly creased side will extend in a generally straight plane.Thus, there is no further tendency for the cells of the honeycombstructure to expand or for the pleats on the one side to fall out.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of the honeycomb structure in its expandedcondition and fabricated in accordance with the teachings of the presentinvention;

FIG. 2 is a schematic view showing the manufacturing process employed inproducing the honeycomb structure of FIG. 1;

FIG. 3 is a perspective view of another embodiment of the honeycombstructure of the present invention;

FIG. 4 is a perspective view of still another embodiment of thehoneycomb structure of the present invention;

FIG. 5 is a cross-sectional view showing the honeycomb structure of FIG.4 in partially collapsed condition; and

FIG. 6 is a schematic view showing the manufacturing process employed inproducing the honeycomb structures of FIGS. 3 and 4.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

FIG. 1 shows a honeycomb structure, generally designated by referencenumber 1, as comprising two separate materials, namely a first material2 and a second material 3. These materials are secured together atspaced intervals to form individual cells 4 having front faces 5 andback faces 6. For the purpose of easy identification, the faces 5 arereferred to as front faces, and the faces 6 as back faces. "Front" and"back" hold no limitation as to the position of the structure, forexample, when used as window coverings in building constructions. Also,"honeycomb" is used in the broad sense to mean connected cells, notnecessarily hexogonal, as described and shown herein. As seen from FIG.1, the front faces of all of the cells are formed from the single pieceof material 2 while the back faces of all of the cells are formed fromthe single piece of material 3.

As shown in FIG. 2, the honeycomb structure 1 is formed by continuouslyfeeding a continuous length of each of the materials 2 and 3longitudinally of their length and in directions extending toward eachother. The material 2 has a first set of transverse creases 7 spacedalong the length of material, and the second material 3 has a similarfirst set of transverse creases 7'. The first material also has a secondset of transverse creases 8 spaced along the length of the material inalternating fashion with the first set of creases 7. Similarly, thesecond piece of material 3 has a second set of transverse creases 8'spaced in alternating fashion with the first set of creases 7'. Thefirst and second set of creases on both materials are formed alternatelyon opposite sides of the material so as to permit the materials tocollapse in the accordion pleated fashion shown in FIG. 2 where thecreases define the edges of the pleats.

As the first and second materials are fed in opposite directions, theyare each fed along a first path in partially collapsed condition. Asthey near each other, they are progressively turned about 90° and fedalong a second common path. With the embodiment of the honeycombstructure shown in FIGS. 1 and 2, the successive pleats 8 and 8' of thetwo pieces of material are brought into overlapping relationship as theyare turned from their first path into the common second and they arethen directly joined together in this overlapping relationship. For thispurpose, adhesive may be applied to one or both of the materialsadjacent the creases 8 and 8'. FIG. 2 shows schematically an adhesiveapplicator at 9 for applying a band of adhesive 10 to one side of eachof the pleats 8. This adhesive may extend the full length of the pleator be applied intermittently.

As the successive pleats 8, 8' are brought into overlappingrelationship, they are supported by suitable backup structure 11 while apressure member 12 moves down onto the overlapped pleats to press theminto adhering relationship. The backup structure 11 can beintermittently moved into and out of supporting relationship and canalso be used to move the combined cell structure downwardly along thesecond common path after each set of pleats is secured together.

As shown in FIGS. 1 and 2, the two materials are joined together at theoverlapped pleats and this joining is immediately adjacent the creases8, 8'. Therefore, these creases are retained for aiding in the foldingof the two materials as the cells are moved to and from collapsed andexpanded condition. It is also seen that the attachment of the cellstogether is intermediate the first set of creases 7, 7'. Thus, thepleats associated with these creases remain for giving the resultinghoneycomb structure a pleated appearance on both sides.

Further, as seen from FIG. 2, the connecting of the adjacent cellstogether is effected while the two materials 2 and 3 are maintained inpartially expanded condition. Thus, any bleeding of adhesive through thematerials during the adhesive application or pressing operation will notcause any severe manufacturing problems as encountered with the priorart where adjacent cells can become improperly secured together andunopenable. With the present invention, it is only necessary that thecells remain in their partially expanded condition until the adhesive isset.

It will also be appreciated that if the bottom cells are pulled from thetop cells as by their own weight and as would occur when hungvertically. The tendency is to collapse the cell structures but not topull the joints apart. With this reduction in stress on the adhesivejoints between the cells, there will be a great deal more latitude intypes of adhesive that may be used, and, in fact, the types of joints bywhich the cells are connected. For example, with the embodiments shownin FIG. 1, wide space stitching could be employed instead of adhesive.Also, heat welding becomes practical, depending on the types ofmaterial, and in some situations, spot connections can be made along thelength of the cells rather than a continuous connection.

Turning to the embodiments shown in FIGS. 3 and 4, the front and backfaces 5 and 6 of the honeycomb structure are not directly connectedtogether as in the embodiment of FIG. 1. Instead, they are connectedtogether by separate strip material 13 disposed between the adjacentcells 4 and extending longitudinally of the cells. The strip materialscan be used to connect the two pieces of material 2 and 3 together inspaced relationship as shown in FIG. 3, or in non-spaced relationship asshown in FIGS. 4 and 5. With the embodiment of FIG. 3, the spacedrelationship of the materials 2 and 3 produces cell structures 4 havingtheir front faces 5 spaced from their back faces 6. This providessuperior insulating qualities due to the cell structure than result withthe embodiments of FIGS. 1 and 4. Also, the spaced relationship providesfor concealment of the cords that may be associated with the honeycombstructure where it is used for a window covering.

FIG. 6 shows schematically the method of manufacture used in producingthe honeycomb structures of FIGS. 3, 4 and 5. With respect to theembodiment shown in FIG. 3, the two pieces of pleated material are fedalong their first path; and as they are turned into the second commonpath, the pleats associated with the creases 8, 8' are brought intolaterally spaced relationship with each other. As each pair ofassociated pleats attain this spaced relationship, a piece of stripmaterial 13 is brought into overlying relationship with the pleats andadhered thereto. For this purpose, suitable support means 11' and acooperating pressure member 12'; similar in construction and operationto corresponding means shown in FIG. 2, is used. Similarly, adhesive canbe applied to each of the materials adjacent the pleats or the stripmaterial can have one side coated with adhesive. This latterconstruction is used in the embodiment shown in FIG. 6.

As with the joining of the adjacent cells of the embodiment of FIG. 1,the strip connection of the embodiment of FIG. 3 is made immediatelyadjacent the creases 8, 8' which define the pleats. Thus, these creasesremain effective to assist in the collapsing and expanding of theadjacent cells.

For constructing the honeycomb structure of FIG. 4 the materials 2 and 3are turned into the second path with the associated pleats in touchingnon-overlapping contact with each other along the associated creases 8,8'.

The embodiment of FIGS. 4 and 5 also shows other features of the presentinvention. More particular, the two pieces of material are connectedtogether with the pleats facing in the same direction as opposed tofacing in opposite directions, as with the emobidment of FIG. 3. Thus,as the structure is collapsed, the arrangement of FIG. 5 will result.

Also, in the embodiment of the invention shown in FIGS. 4 and 5, thefront face 5 of each cell has a greater amount of material extendingbetween adjacent cells than the back face thereof. This is effected byspacing the first and second set of creases 7 and 8 on the firstmaterial 2 by distances greater than the spacing of the creases 7', 8'of the second piece of material 3. To get the straight sided appearanceof FIG. 4, the creases 7', 8' on the material 3 are spaced from eachother by a distance which is equal to one-half the distance any one cellextends between its adjacent cells in the normal expanded condition onthe honeycomb structure. The spacing of these creases this way andforming them so that they generally fall out in the expanded conditionof the cells permits the material 3 to readily assume the straightcondition in FIG. 4 with each of the faces 6 extending in a straightplane between adjacent cells. The creases 7', however, will be formedsufficiently enough to normally direct the back faces to collapseinwardly of the cell as shown in FIG. 5. Finally, with the creases 7 onthe material 2 being permanently formed, they will maintain the firstmaterial in sharp angular configuration in the normal expanded conditionof the structure.

I claim:
 1. The method of fabricating an expandable honeycomb structureof a plurality of cells, one on top of the other, comprising the stepsof:(a) continuously feeding a continuous length of a first materiallongitudinally of said length, said material having a first set oftransverse creases spaced along the length thereof; (b) continuouslyfeeding a continuous length of a second material longitudinally of saidlength and toward said first material, said second material having afirst set of transverse creases spaced along the length thereof; and (c)joining the two materials together intermediate said first sets ofcreases.
 2. The method according to claim 1 wherein:(a) said first andsecond materials each have a second set of transverse creases spacedalong the length thereof in alternating fashion with the first set ofcreases; and (b) said two materials are joined together immediatelyadjacent said second sets of creases.
 3. The method according to claim 2wherein:(a) the first and second sets of creases are formed on oppositesides of said first and second materials to collapse said materials inaccordian pleated fashion with said first and second sets of creasesdefining first and second sets of pleats, respectively; (b) said firstand second materials are fed along first paths toward each other whileat least in partially collapsed condition; (c) said first and secondmaterials are progressively turned into and fed along a second, commonpath; and (d) said materials are connected together along said secondsets of pleats as they are turned into said second path.
 4. The methodaccording to claim 3 wherein said first and second materials are:(a)turned into overlapping relationship at said second sets of pleats andimmediately adjacent said second sets of creases; and (b) joinedtogether in said overlapping relationship.
 5. The method according toclaim 3 further comprising:(a) feeding a piece of strip materialsucessively into overlying relationship with each second set of pleatsof the first and second materials adjacent the second set of creases asthe materials are turned into said second path; and (b) adhering saidstrip material to each of said second set of pleats immediately adjacentsaid second set of creases.
 6. The method according to claim 5wherein:(a) said first and second materials are turned into said secondpath with the second sets of pleats laterally spaced from each other. 7.The method according to any one of claims 3-6 wherein:(a) the first andsecond materials are connected together with the second sets of pleatsfacing in opposite directions.
 8. The method according to claim 5wherein:(a) said first and second materials are turned into said secondpath with the second sets of pleats in touching non-overlapping contactalong the second set of creases.
 9. The method according to claim 8wherein:(a) the first and second materials are connected together withthe second sets of pleats facing in the same direction.
 10. The, methodaccording to any one of claims 1-6, 8 and 9 wherein:(a) the first andsecond sets of creases on said first material are spaced from each otherby a distance greater than the spacing thereof on said second material.11. The method according to claim 10 wherein:(a) the first and secondsets of creases in said second material are spaced from each other byone-half the distance any one cell extends between adjacent cells in thenormal expanded condition of the honeycomb structure.
 12. The methodaccording to claim 11 wherein:(a) the first set of creases on the firstmaterial are formed to maintain the first material in angularconfiguration in the normal expanded condition of the honeycombstructure; and (b) the first set of creases on the second material areformed to fall out to orient the second material in a generally straightplace in the normal expanded condition of the honeycomb structure.